It is estimated by the International Energy Agency that more than 19% of electrical energy demand
globally is used for lighting. As a result, there has been significant effort around the globe in replacing
in-efficient incandescent light sources with higher efficiency solutions. Much of the focus in curbing
this demand at the consumer level has been in programs to drive adoption of compact fluorescent lamps
(CFL). The choice of using CFLs is not without consequence; each bulb contains mercury which, when
not disposed of properly, ends up in landfills. Moreover, the form factor is not ideal for all lighting
applications. An alternative which has been gaining significant attention is phosphor converted “white”
LEDs. LED lumen output and efficacy – the measure of lumen output versus input power - continues to
make significant progress year over year while, at the same time, the cost in terms of lumen/$ is falling.
Beyond energy savings, High brightness LEDs can have lifetimes of greater than 50,000 hours when
properly designed and operated which eliminates the cost of replacing bulbs.
An off-the-shelf halogen desk lamp was used as the basis for a demonstration of the real world
performance of today’s latest production LED light sources. A Cree XLAMP(R) MC-E LED was used
as the light source. This product incorporates 4 LEDs in a single compact package which is ideal for
directed light applications such as MR-16 and Portable Task Lamps. The original lamp was
characterized before and after modification to highlight the real world performance differences.
The DoE ENERGY STAR Standard for Solid State Lighting Luminaires (Version 1.1 - 12/19/08)
includes requirements for a minimum power factor (PF) of 0.7 for portable residential desk lamps.
Typical LED drivers at this power level normally have a PF of 0.5-0.6 which falls below the
requirements. The solution presented here has been specifically designed to exceed the residential
ENERGY STAR(R) PF requirements without the addition of extra circuitry.
声明:本文内容及配图由入驻作者撰写或者入驻合作网站授权转载。文章观点仅代表作者本人,不代表电子发烧友网立场。文章及其配图仅供工程师学习之用,如有内容侵权或者其他违规问题,请联系本站处理。 举报投诉